It's saved us a lot of money. We've hardly noticed a change in our weekly shop since welcoming L, in fact it's a bit cheaper feeding three mouths! We wash nappies 3 times a week and now own about 30 nappies along with reusable wipes.
These nappies vary but are all, bar four bamboo sized nappies, OSFA (One Size Fits All). This adds to the money saving element as they should last from birth to potty training, sometimes OSFA are called BTP. OSFA usually work by using poppers and booster inserts either in one foldable size or with sized boosters.